Special-grouting-based grouting system with adjustable moving cavity pressure and grouting method thereof

ABSTRACT

A grouting system with an adjustable moving cavity pressure. The grouting system includes a master grouting pipe and a plurality of grouting valve pipes connected to the master grouting pipe, each grouting valve pipe is in an annular space within a borehole wall, the grouting valve pipe includes a grouting valve pipe body, and a spraying valve port is on the grouting valve pipe body. A grouting pipe, an air injection pipe and a movable piston are inside the grouting valve pipe body. The air injection pipe is connected with the movable piston to apply an air pressure into the movable piston, and the movable piston applied with the air pressure expands in volume to form a closed cavity between a lower part of the movable piston and the grouting valve pipe body, so that grouting is performed according to the position of the movable piston.

TECHNICAL FIELD

The present disclosure relates to the field of grouting technologies, and in particular to a special-grouting-based grouting system with an adjustable moving cavity pressure and a grouting method thereof.

BACKGROUND

In foundation treatment engineering, pressure grouting is a conventional approach and pressure control becomes a difficult point during a pressure grouting process. A pressure control value is closely related to a geological condition and a buried depth of a pressure grouting mouth, which brings a very severe challenge to the pressure control of single-pipe pressure grouting. For a conventional pressure grouting pipe, the grouting pressure in a single pipe is consistent, and it is difficult to realize different pressures at different depths or different pressures at different geological soil layers.

In a grouting foundation treatment technique, treatment effects and engineering construction costs largely depend on a grouting amount, and the grouting amount largely depends on a grouting pressure. If the pressure is too small, slurry cannot be effectively penetrated and diffused into a soil body; if the pressure is too large, ground heave occurs easily. Thus, the proper control of the grouting pressure can effectively achieve the treatment effects and control the construction costs.

Since the existing grouting pipe and grouting valve pipe can only achieve a single grouting pressure, and thus cannot control different grouting pressures at different depths and different geological soil layers. At present, in most cases, several grouting pipes with a single spraying valve port are adopted to perform grouting for soil layers at different depths, causing the increased number of holes and the increased number of grouting pipes, prolonging the construction period, and increasing the engineering construction costs.

SUMMARY

An object of the present disclosure is to provide a special-grouting-based grouting system with an adjustable moving cavity pressure. The grouting system can perform pressure adjustment for a single grouting valve pipe, thereby realizing special grouting for different target layers and improving site construction efficiency.

To achieve the above object, the present disclosure adopts the following technical solutions.

A special-grouting-based grouting system with an adjustable moving cavity pressure includes a master grouting pipe and a plurality of grouting valve pipes connected on the master grouting pipe. Each grouting valve pipe is located within an annular space within a borehole wall. The grouting valve pipe includes a grouting valve pipe body, and a spraying valve port is disposed on the grouting valve pipe body.

A grouting pipe, an air injection pipe and a movable piston are disposed inside the grouting valve pipe body, and an outer diameter of the movable piston is smaller than an inner diameter of the grouting valve pipe body. The air injection pipe is connected with the movable piston to apply an air pressure into the movable piston, and the movable piston applied with the air pressure expands in volume to form a closed cavity between a lower part of the movable piston and the grouting valve pipe body. Grouting is performed into the grouting valve pipe body according to the position of the movable piston.

The grouting pipe penetrates through the movable piston such that grouting is performed into the grouting valve pipe body through the grouting pipe.

In a preferred solution of the present disclosure, different grouting pressures in different grouting valve pipes are designed by adjusting the air pressure applied into the movable piston through the air injection pipe described above.

In another preferred solution of the present disclosure, a plurality of spraying valve ports described above are disposed, and a valve port protection pad is fixedly connected at each spraying valve port so as to temporarily prevent a target object from blocking the spraying valve port during mounting.

Preferably, the above valve port protection pad is fixed at the corresponding spraying valve port in a binding manner.

Preferably, the above air injection pipe is connected with an air supply apparatus which injects air into the above air injection pipe.

Another object of the present disclosure is to provide a special-grouting-based grouting method with an adjustable moving cavity pressure. The grouting method includes the following steps.

At step S1, each grouting valve pipe is arranged in an annular space within a borehole wall after drilling, and a grouting pipe, an air injection pipe and a movable piston are mounted in a grouting valve pipe body in such a way that their connections are made reliably.

At step S2, air is injected into the air injection pipe, so that the movable piston connected with the air injection pipe gradually expands to form a closed cavity between a lower part of the movable piston and the grouting valve pipe body.

At step S3, when different grouting pressures are needed in different grouting valve pipes according to a geological condition, the grouting pressures in different grouting valve pipes are adjusted according to different amounts of air injected into the air injection pipes in different grouting valve pipes.

At step S4, when a different grouting pressure is needed in the same grouting valve pipe, a closed cavity with a different height is formed between the lower part of the movable piston and the grouting valve pipe by injecting a different amount of air, so as to adjust the grouting pressure in the same grouting valve pipe.

At step S5, step S3 or S4 is repeated until the entire grouting process is completed.

Compared with the prior art, the present disclosure brings the following beneficial effects.

The present disclosure provides a special-grouting-based grouting system with an adjustable moving cavity pressure. By applying a different air pressure into the movable piston through the air injection pipe, a closed cavity with a different height is formed to adjust the pressure in a single grouting valve pipe. Thus, multi-layer grouting can be realized for the single grouting valve pipe, and different grouting pressures may be designed for different layers according to geological condition and spraying depth. In this way, special grouting may be performed for a target soil layer by using the grouting valve pipe of the present disclosure, thereby realizing multi-layer grouting using the single grouting valve pipe. Therefore, the site construction efficiency can be greatly improved, additional drilling is avoided, and engineering construction costs are saved.

In the present disclosure, a plurality of grouting valve pipes are connected with the master grouting pipe to realize pressure adjustment to different grouting valve pipes. For example, different pressures may be maintained in different grouting valve pipes by applying different air pressures into the movable pistons through the air injection pipes in different grouting valve pipes. Therefore, site construction requirements can be satisfied.

Compared with the prior art, the special-grouting-based grouting system with an adjustable moving cavity pressure in the present disclosure can realize the pressure adjustment to the single grouting valve pipe or to different grouting valve pipes, and thus it is worth promotion and application.

BRIEF DESCRIPTION OF THE DRAWINGS

The present disclosure is further described below in combination with accompanying drawings.

FIG. 1 is a structural schematic diagram of a single grouting valve pipe according to the present disclosure.

FIG. 2 is a structural schematic diagram of a special-grouting-based grouting system with an adjustable moving cavity pressure according to the present disclosure.

Numerals of the drawings are described as follows: 1-grouting valve pipe body, 2-movable piston, 3-grouting pipe, 4-air injection pipe, 5-spraying valve port, 6-valve port protection pad, 7-slurry supply apparatus, and 8-air supply apparatus.

DETAILED DESCRIPTION OF THE EMBODIMENTS

The present disclosure provides a special-grouting-based grouting system with an adjustable moving cavity pressure. To make the advantages and technical solutions of the present disclosure clearer, the present disclosure will be described in detail below in combination with specific examples.

Unless otherwise clearly specified, the term “include” or its variations such as “comprise” in the entire specification and the claims will be understood as including the stated parts or components rather than excluding other parts or other components.

In the specification, for convenience of description, the relative spatial terms such as “under”, “below”, “lower”, “over”, “above” and “upper” may be used to describe a relationship between one component or feature and another component or feature in the drawings. It is to be understood that the relative spatial terms are intended to include different directions in which an object is used or operated in addition to the directions drawn in the drawings. For example, if an object in the drawing is turned over, a component “under” or “below” another component or feature will be described as oriented to be “above” the another component or feature. Therefore, the exemplary term “below” may include two directions. i.e. below or above. The component may also have another orientation (for example, rotated by 90 degrees or in other orientations), and the relative spatial terms used herein are to be explained accordingly.

The present disclosure provides a special-grouting-based grouting system with an adjustable moving cavity pressure. As shown in FIG. 2, the grouting system mainly includes a master grouting pipe and a plurality of grouting valve pipes connected to the master grouting pipe. During actual grouting, each grouting valve pipe is located in an annular space within a borehole wall. For the grouting valve pipe as a main improvement of the present disclosure, grouting is performed to the master grouting pipe through a slurry supply apparatus 7, and then performed to each grouting valve pipe through the master grouting pipe, as shown in FIG. 1. The grouting valve pipe includes a grouting valve pipe body 1, a plurality of spraying valve ports 5 are disposed on the grouting valve pipe body 1, the plurality of spraying valve ports 5 may be for example, arranged in equal distance from bottom to top, or may be disposed at the same horizontal position of the grouting valve pipe body 1. The disposal of the spraying valve port 5 may be reasonably made by persons skilled in the art according to different geological conditions. When grouting is performed into the grouting valve pipe body through a grouting pipe, grouting is performed into the surrounding soil body through the spraying valve ports 5.

A grouting pipe 3, an air injection pipe 4 and a movable piston 2 are disposed inside the grouting valve pipe body. The grouting pipe 3 may be made of a common material of a grouting pipe for grouting in the prior art. The air injection pipe 4 is connected with an air supply apparatus 8 to provide air. An outer diameter of the movable piston is smaller than an inner diameter of the grouting valve pipe body. When air is supplied to the movable piston, the movable piston may expand to form a closed space with the grouting valve pipe body. The bottom of the air injection pipe is connected with the movable piston, and the top of the air injection pipe is connected with the air supply apparatus. When the air supply apparatus supplies air into the air injection pipe, the air enters the movable piston from the bottom of the air injection pipe, so that an air pressure is applied into the movable piston through the air injection pipe. The movable piston applied with the air pressure expands in volume to form a closed cavity between a lower part of the movable piston and the grouting valve pipe body. The grouting is performed into the grouting valve pipe body according to the position of the movable piston.

The above grouting pipe penetrates through the movable piston to perform grouting into the grouting valve pipe body.

As a preferred solution of the present disclosure, to prevent the surrounding soil from blocking the spraying valve ports during the mounting of the apparatus, a valve port protection pad 6 is fixed at each spraying valve port. The valve port protection pad 6 has a larger area than the spraying valve port, and preferably is fixed at the spraying valve port in a binding manner.

In the present disclosure, different pressures may be applied to a single grouting valve pipe. For example, during a grouting process, a certain amount of air is firstly injected into the movable piston to enable the movable piston to expand to a certain height, and at this time, a closed cavity is formed between the lower part of the movable piston and the grouting valve pipe body, and grouting can be performed by applying a pressure to the grouting pipe at this time. Then, air injection into the movable piston is continued to enable the movable piston to further expand to a height greater than that of the initial expansion, so as to form another closed cavity between the lower part of the movable piston and the grouting valve pipe body, and thus grouting can be performed by applying a different pressure to the grouting pipe at this time.

In the present disclosure, the pressure of the single grouting valve pipe can be adjusted during one-time grouting. For example, different amounts of air are injected into different grouting valve pipes to form closed cavities with different heights between the movable pistons and the grouting valve pipe bodies, thereby realizing grouting by applying different pressures to the grouting pipes.

The grouting method of the present disclosure will be further described below in combination with the above special-grouting-based grouting system with an adjustable moving cavity pressure.

Example 1

When it is required to apply different pressures to a single grouting valve pipe, multi-layer grouting may be realized using the single grouting valve pipe by forming closed cavities at different heights between the movable piston and the grouting valve pipe body, with a different grouting pressure designed for each layer according to the geological condition and the spraying depth. In this way, special grouting may be performed to the target soil layer and multi-layer grouting may be realized using the single grouting pipe in the present disclosure, thereby improving the site construction efficiency.

The grouting method specifically includes the following steps.

At step 1, the position of the spraying valve port is designed according to the geological condition.

At step 2, on-site paying-off is performed to determine the position of the grouting valve pipe and a borehole is drilled using a well drilling machine.

At step 3, the grouting valve pipe body is mounted, and the movable piston, the grouting pipe and the air injection pipe are placed inside the grouting valve pipe body according to the design of the present disclosure.

At step 4, a grouting position is determined, and pressurized air injection is performed to the movable piston to form a closed cavity.

At step 5, pressurized grouting is performed for the grouting pipe by selecting a designed pressure according to factors such as geological condition and grouting depth.

At step 6, the movable piston is moved to above the upper layer of the spraying valve ports, and injected with air under pressure again to form a second closed cavity.

At step 7, the pressurized grouting is performed for the grouting pipe by selecting another designed pressure according to factors such as geological condition and grouting depth.

At step 8, steps 6 and 7 are repeated until the entire grouting process is completed.

Example 2

As shown in FIG. 2, when the grouting system is applied to different strata such as sand layer and soil layer, it is required to apply different pressures to different grouting valve pipes. At this time, grouting is performed for different grouting valve pipes by forming closed cavities with different heights between the movable pistons and the grouting valve pipe bodies respectively.

The specific grouting method includes the following steps.

At step 1, the position of the spraying valve port is designed according to the geological condition.

At step 2, on-site paying off is performed to determine the positions of the grouting valve pipes and boreholes are drilled using a well drilling machine.

At step 3, the grouting valve pipe bodies are mounted, and the movable piston, the grouting pipe and the air injection pipe are placed inside the grouting valve pipe body according to the design of the present disclosure.

At step 4, the grouting position of each grouting valve pipe is determined respectively, and pressurized air injection is performed into the respective movable piston of each grouting valve pipe to form a closed cavity with a different height.

At step 5, pressurized grouting is performed into each grouting valve pipe; if the grouting pressure is to be further adjusted, the adjustment may be performed based on the height of the closed cavity between the movable piston and the grouting valve pipe body.

At step 6, steps 4 and 5 are repeated until the entire grouting process is completed.

The preferred examples of the present disclosure are described above in combination with the accompanying drawings. However, the present disclosure is not limited herein.

Terms such as grouting valve pipe body, movable piston, grouting pipe and air injection pipe are repeatedly used herein without excluding the possibility of using other terms. These terms are merely used to describe and explain the essence of the present disclosure more conveniently, and it is contrary to the spirit of the present disclosure to interpret these terms as any additional limitation.

It is further to be noted that the specific examples described herein are merely illustrative of the spirit of the present disclosure. Persons skilled in the art may make various modifications or supplementations or substitutions in a similar manner to the described specific examples without departing from the spirit of the present disclosure or surpassing the scope defined in the appended claims. 

1. A special-grouting-based grouting system with an adjustable moving cavity pressure, comprising a master grouting pipe and a plurality of grouting valve pipes connected to the master grouting pipe, wherein each grouting valve pipe is located in an annular space within a borehole wall; the grouting valve pipe comprises a grouting valve pipe body, and a spraying valve port is disposed on the grouting valve pipe body; wherein a grouting pipe, a air injection pipe and a movable piston are disposed inside the grouting valve pipe body, an outer diameter of the movable piston is smaller than an inner diameter of the grouting valve pipe body, the air injection pipe is connected with the movable piston to apply an air pressure into the movable piston, and the movable piston applied with the air pressure expands in volume to form a closed cavity between a lower part of the movable piston and the grouting valve pipe body, so that grouting is performed for the grouting valve pipe body according to the position of the movable piston; the grouting pipe penetrates through the movable piston to perform grouting into the grouting valve pipe body.
 2. The special-grouting-based grouting system with an adjustable moving cavity pressure according to claim 1, wherein a different grouting pressure in each grouting valve pipe is designed by adjusting a size of the air pressure applied into the movable piston through the air injection pipe.
 3. The special-grouting-based grouting system with an adjustable moving cavity pressure according to claim 1, wherein a plurality of spraying valve ports are disposed, and a valve port protection pad is fixedly connected at each spraying valve port to temporarily prevent a target object from blocking the spraying valve port during mounting.
 4. The special-grouting-based grouting system with an adjustable moving cavity pressure according to claim 3, wherein the valve port protection pad is fixed at the corresponding spraying valve port in a binding manner.
 5. The special-grouting-based grouting system with an adjustable moving cavity pressure according to claim 1, wherein the air injection pipe is connected with an air supply apparatus which injects air into the air injection pipe.
 6. A special-grouting-based grouting method with an adjustable moving cavity pressure using the special-grouting-based grouting system with an adjustable moving cavity pressure according to claim 1, comprising the following steps sequentially: at step S1, arranging each grouting valve pipe in an annular space within a borehole wall after drilling, and mounting the grouting pipe, the air injection pipe and the movable piston in the grouting valve pipe body while ensuring the connections of the device are made fully and reliably; at step S2, injecting air into the air injection pipe to enable the movable piston connected with the air injection pipe to gradually expand so as to form a closed cavity between the lower part of the movable piston and the grouting valve pipe body; at step S3, when different grouting pressures are needed in different grouting valve pipes according to a geological condition, adjusting the grouting pressures in different grouting valve pipes according to different amounts of air injected into the air injection pipes in different grouting valve pipes; at step S4, when a different grouting pressure is needed in the same grouting valve pipe, forming a closed cavity with a different height between the lower part of the movable piston and the grouting valve pipe by injecting a different amount of air, so as to adjust the grouting pressure in the same grouting valve pipe; and at step S5, repeating step S3 or S4 until the entire grouting process is completed. 